Siobhan C.
Sample The IPv6 warning hit home
We had IPv6 enabled with no firewall rules for it. Found and fixed thanks to this course.
Network security basics: firewalls, VPNs and segmentation
Design and defend networks with firewall rules, segmentation, WireGuard VPNs, TLS, DNS protections and network monitoring with Suricata and Zeek
Created by Levan Kapanadze
- Updated September 2026
- English
- Intermediate
What you will learn
- Describe how TCP, UDP, ports and addresses relate to attack surface
- Write stateful firewall rules with nftables and review cloud security groups
- Design network segments that limit lateral movement
- Set up a WireGuard VPN and explain when zero trust access is a better fit
- Explain what TLS and DNS security controls do and do not protect
- Detect suspicious traffic with Suricata and analyse it with Zeek logs
Course content
Networks through a security lens
Remote access and VPNs
- Video: How VPNs work 9 min
- Video: Setting up WireGuard 12 min
- Article: IPsec and legacy VPN appliances 9 min
- Video: Zero trust access 10 min
TLS, certificates and DNS
- Video: What TLS protects and what it does not 10 min
- Article: Certificates, PKI and automation 9 min
- Video: DNS as an attack surface 10 min
- Video: Protective DNS and encrypted DNS 9 min
Monitoring and detection
- Article: What to log on a network 9 min
- Video: Intrusion detection with Suricata 12 min
- Video: Network analysis with Zeek 11 min
- Article: Spotting command and control traffic 9 min
Hardening network services
- Video: Securing SSH and remote administration 9 min
- Video: Email security: SPF, DKIM and DMARC 10 min
- Article: Network device hygiene 8 min
Wireless, cloud and resilience
- Video: Securing Wi-Fi in the office 9 min
- Video: Cloud network security 11 min
- Article: Denial of service basics 9 min
- Video: A network security review 10 min
- Quiz: Final check 6 min
Requirements
- Basic Linux command line skills
- A general understanding of IP addresses
- A computer able to run three small virtual machines
Description
Networks connect everything, which makes them both a target and a powerful place to defend. This course teaches the network security concepts that every IT professional, developer working with infrastructure and aspiring security engineer should understand, with hands on labs that run on your own computer.
What you will learn
- How traffic flows: addresses, ports, TCP and UDP, and what an attacker sees from outside
- Stateful firewalls and writing rules with nftables, and how cloud security groups compare
- Segmentation with VLANs and subnets, and why flat networks make attacks easy
- Remote access with WireGuard and IPsec VPNs, and the move towards zero trust access
- TLS and certificates, and what they protect
- DNS as both an attack surface and a defensive tool
- Network monitoring and intrusion detection with Suricata and Zeek
How the course works
We build a small lab network of virtual machines representing an office, a server segment and the internet. You will scan it, write firewall rules, split it into segments, connect remote users with WireGuard and watch an attack appear in intrusion detection logs. Every lab includes instructions for cleaning up.
You should know basic Linux commands and have a general idea of what an IP address is. Everything else is explained as we go.
Who this course is for
- IT administrators responsible for office or server networks
- Developers and DevOps engineers working with cloud networking
- Students preparing for security or networking roles
Instructor
Levan Kapanadze
Security engineer teaching security fundamentals, identity and network defence in plain language
- 4.3 instructor rating
- 21 reviews
- 7,370 students
- 3 courses
- Sample
I work on security for engineering organisations: access control, network design reviews, incident response and a lot of patient explaining. I believe most security problems are solved by clear habits rather than expensive tools.
My courses are for developers, IT staff and curious beginners who want to understand how attacks really happen and which controls actually reduce risk. We cover passwords and passkeys, MFA, least privilege, segmentation, logging and how to respond when something goes wrong.
I avoid fear based teaching. You will leave each course with a short list of concrete changes you can make at work or at home this week.
Student reviews
Gustavo L.
Sample Segmentation lab was excellent
Watching the simulated attacker fail to reach the database after splitting the network made segmentation very concrete.
Ingrid B.
Sample nftables explained clearly
We moved our servers from old iptables scripts to nftables using the example ruleset as a start.
Kenji O.
Sample Great WireGuard lesson
Setting AllowedIPs carefully and adding firewall rules for VPN users was very practical. Zeek lesson was dense.
Tomasz W.
Sample Clear zero trust explanation
The comparison of VPNs and identity aware proxies helped us plan our next year.
Aaliyah M.
Sample Good mix of concepts and labs
Not too theoretical. The external view lesson changed how I think about what we expose.
Pavel R.
Sample Useful, lab needs resources
Content is strong, but running the lab machines on my laptop was slow. Cloud VMs worked better.
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